This invention relates to a power transmission device for use in a motor vehicle, the device being particularly suitable for tractors.
In an agricultural tractor, an engine is usually mounted on a front part of the tractor body and a transmission case is usually mounted on a rear part thereof. The main shaft of the engine is connected to a propeller shaft by a main clutch. The propeller shaft extends backwards along the tractor body and is connected to an input shaft axially supported on the transmission case. The transmission case contains a shift mechanism. The power of the engine which is input to the input shaft is transmitted to the main shaft through the shift mechanism. The rear wheels are driven by the main shaft. In the case of a four-wheel drive, the main shaft is further connected to a front-wheel drive propeller shaft and the propeller shaft extends forwards from the transmission case to drive the front wheels. The transmission case is further provided with aPTO shaft. The power of the engine is also transmitted to this PTO shaft and is then transmitted to a machine connected to the tractor through the PTO shaft.